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When we add or subtract time, remember that we are working with hours, minutes and seconds.

60 seconds = 1 minute

60 minutes = 1 hour

Example: 1h 45min.+ 2h 36min. You will think of your own way to do this.

One way might be:

1h 45min. +2h 36min. = 3h 81min. (Notice: there is 1h hidden in those minutes.)

= 4h 21min.

7. Calculate the answers and write down your calculations:

7.1 53 min. and 48 sec. + 14 min. and 34 sec

7.2 14 h 25 min. - 7 h 36 min.

Activity 4:

To describe and illustrate ways of measuring and representing time in different cultures throughout history [LO 4.4]


Your educator will help you to find reference books or take you to the library when you need information in this Assignment.

1. Read the following information.

People in the Ancient World did not have clocks and watches as we know them, but they did try to measure time. Some of their instruments for measuring time included: a sun dial; a water clock; a candle clock; burning oil and an hour-glass. Some of them were not very accurate.

2. Look up information in reference books or on the computer to find out what these instruments looked like and how they worked. Also try to find out which people used them and where they lived.

3. Choose four of the instruments named in number 1. Draw them and label each drawing clearly.

4. Explain how any two of them worked.

5. Make either a water clock or a candle clock (or one of the others) and show it to the class. Explain to the class how it works.

6. In the table below write down which people used each of the clocks you have drawn and where they lived:

Name of clock People who used it Where they lived

7. Explain why these ancient instruments were not always very accurate. Write your answer below.

8. Try to think of a link between one of them and a modern instrument which we use. Write down your answer .


LO 4
measurementThe learner will be able to use appropriate measuring units, instruments and formulae in a variety of contexts.
We know this when the learner:
4.1 reads, tells and writes analogue, digital and 24-hour time to at least the nearest minute and second;
4.2 solves problems involving calculation and conversion between appropriate time units including seconds, minutes, hours, days, weeks, months and years;
4.3 uses time-measuring instruments to appropriate levels of precision, including watches and clocks;
4.4 describes and illustrates ways of measuring and representing time in different cultures throughout history;
4.5 estimates, measures, records, compares and orders two-dimensional shapes and three-dimensional objects using S.I. units with appropriate precision for:
  • mass using grams (g) and kilograms (kg);
  • capacity using millilitres (ml) and litres (l);
  • length using millimetres (mm), centimetres (cm), metres (m) and kilometres (km);
4.6 solves problems involving selecting, calculating with and converting between appropriate S.I. units listed above, integrating appropriate context for Technology and Natural Sciences;
4.7 uses appropriate measuring instruments (with understanding of their limitations) to appropriate levels of precision including:
  • bathroom scales, kitchen scales and balances to measure mass;
  • measuring jugs to measure capacity;
  • rulers, metre sticks, tape measures and trundle wheels to measure length;
4.8 investigates and approximates (alone and/or as a member of a group or team):
  • perimeter, using rulers or measuring tapes.



1.1 2

1.2 5

1.3 7

Practical work


1.1 20 to 11 or 10.40

1.2 9.25 or 25 past 9

2 Drawing hands on clock faces (see module)


1.1 05:10

1.2 16:20

1.3 21:45

1.4 00:57 or 24:57

  • 20:00
  • 09:59

2.1 06:45

2.2 16:10

3.1 Drawing on clock-face: ten to two in the afternoon

3.2 Drawing on a clock-face: ten past nine in the morning

4. Morning; the hour hand is on the right side of the clock-face; in the afternoon it would be on the left side of this clock-face.

5.1 1 min. 17,53s

5.2 5 min. 56,01s

ACTIVITY 3 problems involving time

1.1 Kathleen

1.2 Her time is the shortest

1.3 0,9s

2. 13:00 or 1 p.m

3.1 Flight 502: afternoon; Flight 504: evening

  • Flight 504 was 5 min. faster.

4. 7 h 40 min.

5.1 8 April 2003

5.2 5 December 2003

5.3 10 days

5.4 3 weeks 3 days

5.5 1 weeks 2 day

  • The time from one morning high tide to the next increases; the increase varies from one minute to four minutes
  • The time from one afternoon high tide to the next increases; the increase varies from one minute to 3 minutes.

( Note : from morning high tide to afternoon high tide on the same day the time seems to decrease by 1min.each day, but not on 3 July.)

  • 04:14
  • 12 h 26 min.

7.1 1h 8 min. 22 s.

7.2 6 h 49 min.

ACTIVITY 4 assignments

1. Read

2. Look up information

3.1 Drawings

3.2 Practical and oral

3.3 Own – practical and oral

3.4 Own – complete table

4. They could not measure seconds and parts of seconds; outside conditions (e.g. wind) influenced the instruments.

5. hour-glass; egg-timer

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
Read about ancient clocks like_ hour glass, water clock and sun dial for a quiz and hand on Activity in the class
Neha Reply

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Source:  OpenStax, Mathematics grade 4. OpenStax CNX. Sep 18, 2009 Download for free at http://cnx.org/content/col11101/1.1
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